Control apparatus for transmission

ABSTRACT

A control apparatus for a transmission including a gear engagement commander outputting a gear engagement command of a sleeve, an actuator controller controlling an actuator to move the sleeve from a neutral position to a gear engaging position when the gear engagement command is output, a gear engagement determiner determining whether an engagement of the sleeve is prevented in a course of moving the sleeve from the neutral position to the gear engaging position; and a motor controlling an electric motor to rotate a rotating shaft so as to change a rotational position of movable dog teeth relative to passive dog teeth when it is determined that the engagement of the sleeve is prevented.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2016-087627 filed on Apr. 26, 2016, thecontent of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION Field of the Invention

This invention relates to a control apparatus for a transmission forcontrolling an engagement of dog teeth.

Description of the Related Art

Conventionally, an apparatus is known that includes a sleeve mounted tobe axially movable on a hub that rotates integrally with a rotatingshaft of a transmission and a gear arranged beside the sleeve to berotatable relative to the rotating shaft, and that, when an engagementof dog teeth provided on the sleeve with dog teeth provided on the gearfails, reattempt the engagement of the dog teeth with each other. Theapparatus described in Japanese Unexamined Patent Publication NO.10-29984 (JPH10-29984A), for example, when sleeve movement for engagingthe dog teeth is instructed but the sleeve nevertheless does not move toa desired position, the sleeve is once returned to a pre-movementneutral position and the engagement of the dog teeth with each other isreattempted a predetermined time later.

However, in the apparatus described in JPH10-29984A, since the sleeve isreturned to the neutral position to reattempt the engagement when theengagement fails, it takes time to complete the engagement and shiftoperations are hard to perform rapidly.

SUMMARY OF THE INVENTION

An aspect of the present invention is a control apparatus for atransmission, and the transmission includes a rotating shaft rotatableby an electric motor; a hub configured to rotate integrally with therotating shaft; a sleeve including movable dog teeth and supported onthe hub through the movable dog teeth in a manner movable in an axialdirection; a rotor arranged beside the sleeve in the axial direction ina manner rotatable relative to the rotating shaft and including passivedog teeth engageable with the movable dog teeth; and an actuatorconfigured to move the sleeve from a neutral position where the movabledog teeth is apart from the passive dog teeth so that the rotor isrotatable relative to the rotating shaft to a gear engaging positionwhere the movable dog teeth engage with the passive dog teeth so thatthe rotor is rotatable integrally with the rotating shaft to establish apredetermined speed stage. The control apparatus includes a processorconfigured to perform: outputting a gear engagement command of thesleeve; controlling the actuator to move the sleeve from the neutralposition to the gear engaging position when the gear engagement commandis output; determining whether an engagement of the sleeve is preventedin a course of moving the sleeve from the neutral position to the gearengaging position by the actuator; and controlling the electric motor torotate the rotating shaft so as to change a rotational position of themovable dog teeth relative to the passive dog teeth when it isdetermined that the engagement of the sleeve is prevented.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects, features, and advantages of the present invention willbecome clearer from the following description of embodiments in relationto the attached drawings, in which:

FIG. 1 is a diagram showing schematically part of a configuration of atransmission to which a control apparatus according to an embodiment ofthe present invention is applied;

FIG. 2 is a diagram of two-dimensional developments of dog teeth of afirst speed drive gear and dog teeth of a sleeve included in thetransmission of FIG. 1, and is the diagram showing an example of a phasebetween the dog teeth;

FIG. 3 is a diagram of two-dimensional developments of dog teeth of thefirst speed drive gear and dog teeth of the sleeve included in thetransmission of FIG. 1, and is the diagram showing another example of aphase between the dog teeth;

FIG. 4 is a timing chart showing an example of an operation in thecontrol apparatus according to the embodiment of the present invention;

FIG. 5A is a block diagram showing a configuration of the controlapparatus for the transmission according to the embodiment of thepresent invention;

FIG. 5B is a block diagram showing a functional configuration of acontroller of FIG. 5A;

FIG. 6 is a flowchart showing an example of processing executed by thecontroller of FIG. 5A; and

FIG. 7 is a timing chart showing an example of an operation differentfrom FIG. 4.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, an embodiment of the present invention is explained withreference to FIGS. 1 to 7. FIG. 1 is a diagram schematically showingpart of a configuration of a transmission to which a control apparatusaccording to an embodiment of the present invention is applied. Thistransmission is mounted on a hybrid vehicle, for example. The hybridvehicle includes an engine 2 and an electric motor 3.

The transmission 1 includes a gear mechanism 10 for changing rotationalspeed of at least one of the engine 2 and the electric motor 3 at speedratios in accordance with speed stages and a clutch mechanism C fortransmitting or not transmitting torque of the engine 2 to the gearmechanism 10. Torque output through the gear mechanism 10 is transmittedto drive wheels through a differential gear mechanism, a drive shaft andthe like (none of which are shown), thus driving the vehicle.Alternatively, torque of the engine 2 acting as a prime mover can beoutput to the transmission 1 through a torque converter.

The gear mechanism 10 includes multiple rotatably supported rotatingshafts arranged substantially in parallel with one another, i.e., afirst main input shaft 11, a second main input shaft 12, an auxiliaryinput shaft 13, an output shaft 14, an idler shaft 15, and a reverseshaft 16. The second main input shaft 12 is formed hollow so as toconcentrically enclose the first main input shaft 11. The transmission 1is, for example, an automatic transmission with seven forward speeds andone reverse speed. The clutch mechanism C is, for example, constitutedas a dry dual clutch including a first clutch C1 and a second clutch C2.

The electric motor 3 is, for example, constituted as a three-phase DCbrushless motor having a rotor 3 a rotatably supported inside a housing(not shown) of the electric motor 3 and a stator 3 b fixed on thehousing to surround the rotor 3 a. One end of the first main input shaft11 is connected to the rotor 3 a of the electric motor 3, and the firstmain input shaft 11 can rotate integrally with the rotor 3 a. The stator3 b includes a coil wound around a stator core, and the coil iselectrically connected through a power drive unit to a battery.Operation of the power drive unit is controlled by a controller (FIG.5A) serving as an electronic control unit (ECU). This enables torqueproduced by the electric motor 3 to be controlled and the controlledtorque of the electric motor 3 to be input to the first main input shaft11. During vehicle braking, regenerated energy can be input to theelectric motor 3.

The other end of the first main input shaft 11 is connected through thefirst clutch C1 to an output shaft 2 a of the engine 2, and the firstmain input shaft 11 and output shaft 2 a are connected or disconnectedin accordance with engagement or disengagement of the first clutch C1.More specifically, when the first clutch C1 engages, the first maininput shaft 11 and output shaft 2 a are connected and torque from theengine 2 is input to the first main input shaft 11. On the other hand,when the first clutch C1 disengages, the first main input shaft 11 andoutput shaft 2 a are disconnected and input of torque from the engine 2is cut off.

The first clutch C1 is a clutch for odd-numbered speed stages, and afirst speed drive gear 21, a third speed drive gear 23, a seventh speeddrive gear 27 and a fifth speed drive gear 25 are arranged on the firstmain input shaft 11 in this order from the electric motor 3 side. Inother words, the first main input shaft 11 is a rotating shaft forodd-numbered speed stages. The drive gears 21, 23, 25 and 27 aresupported on the outer peripheral surface of the first main input shaft11 through associated bearings so as to be rotatable relative to thefirst main input shaft 11. The first speed drive gear 21 and the thirdspeed drive gear 23 are provided to be integrally rotatable.

A planetary gear unit 20 is disposed between the rotor 3 a of theelectric motor 3 and the first speed drive gear 21. The planetary gearunit 20 includes a sun gear 20 a fixed on the first main input shaft 11,a ring gear 20 c installed around the sun gear 20 a, a planetary gear 20b disposed between the sun gear 20 a and the ring gear 20 c and meshedwith the sun gear 20 a and the ring gear 20 c, and a carrier 20 d whichrotatably supports the planetary gear 20 b. The sun gear 20 a and thecarrier 20 d are both mounted to be rotatable around the first maininput shaft 11, and the ring gear 20 c is fixed to a casing 1 a of thetransmission 1. Therefore, rotation of the sun gear 20 a rotates thecarrier 20 d at a rotational speed proportional to the rotational speedof the sun gear 20 a.

In the present specification, when it is stated that a gear is fixed ona rotating shaft 11 to 16, this is meant to include a case in which thegear is machined on an outer peripheral surface of a rotating shaft 11to 16 and a case in which a gear separate from a rotating shaft 11 to 16is supported on the rotating shaft 11 to 16 by spline coupling or thelike, i.e., cases in which a gear is provided on a rotating shaft 11 to16 to be incapable of relative rotation.

One end of the second main input shaft 12 is connected through thesecond clutch C2 to the output shaft 2 a of the engine 2, and the secondmain input shaft 12 and output shaft 2 a are connected or disconnectedin accordance with engagement or disengagement of the second clutch C2.More specifically, when the second clutch C2 engages, the second maininput shaft 12 and output shaft 2 a are connected and torque from theengine 2 is input to the second main input shaft 12. On the other hand,when the second clutch C2 disengages, the second main input shaft 12 andoutput shaft 2 a are disconnected and input of torque from the engine 2is cut off.

A gear 31 is fixed on the other end of the second main input shaft 12.The gear 31 meshes with an idler gear 32 fixed on the idler shaft 15,and the idler gear 32 meshes with a gear 33 fixed on the auxiliary inputshaft 13. Torque of the second main input shaft 12 is thereforetransmitted through the idler gear 32 to the auxiliary input shaft 13,whereby the auxiliary input shaft 13 rotates together with the secondmain input shaft 12.

The second clutch C2 is a clutch for even-numbered speed stages, and asecond speed drive gear 22, a sixth speed drive gear 26 and a fourthspeed drive gear 24 are arranged on the auxiliary input shaft 13 in thisorder from the electric motor 3 side. In other words, the auxiliaryinput shaft 13 is a rotating shaft for even-numbered speed stages. Thedrive gears 22, 24 and 26 are supported on the outer peripheral surfaceof the auxiliary input shaft 13 through associated bearings so as to berotatable relative to the auxiliary input shaft 13.

A gear 34 is fixed on one end of the reverse shaft 16. The gear 34meshes with the idler gear 32, whereby torque of the second main inputshaft 12 is input to the reverse shaft 16. A reverse drive gear 28 issupported on the outer peripheral surface of the reverse shaft 16through a bearing so as to be rotatable relative to the reverse shaft16. The reverse drive gear 28 meshes with a reverse driven gear 35 fixedon the first main input shaft 11 between the fifth speed drive gear 25and the gear 31.

A second-third speed driven gear 41, a sixth-seventh speed driven gear42, a fourth-fifth speed driven gear 43, a parking gear 44 and a finalgear 45 are fixed on the output shaft 14 in this order from the electricmotor 3 side. The second-third speed driven gear 41 meshes with thesecond speed drive gear 22 and the third speed drive gear 23. Thesixth-seventh speed driven gear 42 meshes with the sixth speed drivegear 26 and the seventh speed drive gear 27. The fourth-fifth speeddriven gear 43 meshes with the fourth speed drive gear 24 and the fifthspeed drive gear 25.

The parking gear 44 engages an engaging pawl of a parking gear mechanism(not shown), and the gear mechanism 10 can be locked and unlocked inaccordance with operation of the parking gear mechanism. Torque of thetransmission 1 is output through the final gear 45 to the differentialgear mechanism (not shown).

The transmission 1 includes a first speed synchronization mechanism SY1which connects the first speed drive gear 21 rotatable with respect tothe first main input shaft 11 to the first main input shaft 11, athird-seventh speed synchronization mechanism SY2 which connects one ofthe third speed drive gear 23 and fifth speed drive gear 25 rotatablewith respect to the first main input shaft 11 to the first main inputshaft 11, a fifth speed synchronization mechanism SY3 which connects thefifth speed drive gear 25 rotatable with respect to the first main inputshaft 11 to the first main input shaft 11, a second-sixth speedsynchronization mechanism SY4 which connects one of the second speeddrive gear 22 and sixth speed drive gear 26 rotatable with respect tothe auxiliary input shaft 13 to the auxiliary input shaft 13, a fourthspeed synchronization mechanism SY5 which connects the fourth speeddrive gear 24 rotatable with respect to the auxiliary input shaft 13 tothe auxiliary input shaft 13, and a reverse synchronization mechanismSY6 which connects the reverse drive gear 28 rotatable with respect tothe reverse shaft 16 to the reverse shaft 16.

The first speed synchronization mechanism SY1 includes a hub HB1 fixedto an outer peripheral surface of the carrier 20 d of the planetary gearunit 20 and a substantially cylindrical sleeve SL1 disposed around thehub HB1. An outer peripheral surface of the hub HB1 and an innerperipheral surface of the sleeve SL1 are formed with dog teeth (splines)D1 and D2, respectively, and the sleeve SL1 is engagingly supported viathe dog teeth D1 and D2 to be axially movable along the outer peripheralsurface of the hub HB1. Dog teeth D3 identical in diameter and pitch tothe dog teeth D1 of the hub HB1 are formed on an outer peripheralsurface of the first speed drive gear 21 concentrically with the dogteeth D1 of the hub HB1.

The sleeve SL1 is moved axially by an actuator (for example, electricmotor) operating through a fork (not shown). When the sleeve SL1 is inneutral position as illustrated, the dog teeth D2 of the sleeve SL1 areseparated from the dog teeth D3 of the first speed drive gear 21. Atthis time, the hub HB1 is rotatable with respect to the first speeddrive gear 21.

When the sleeve SL1 is moved from neutral position toward the firstspeed drive gear 21 and reaches a first speed in-gear position, the dogteeth D2 of the sleeve SL1 engage (go in gear) with the dog teeth D3 ofthe first speed drive gear 21. As a result, the first speed drive gear21 is connected to the first main input shaft 11 through the sleeve SL1,hub HB1, carrier 20 d and sun gear 20 a, whereby the first speed drivegear 21 can rotate integrally with the first main input shaft 11. Whenthe first clutch C1 engages in this state, the first speed stage isestablished and rotation of the first main input shaft 11 is transmittedto the output shaft 14 through the sun gear 20 a, planetary gear 20 b,carrier 20 d, hub HB1, first speed drive gear 21, third speed drive gear23 and second-third speed driven gear 41, thus driving the vehicle inthe first speed stage.

The third-seventh speed synchronization mechanism SY2, fifth speedsynchronization mechanism SY3, second-sixth speed synchronizationmechanism SY4, fourth speed synchronization mechanism SY5, and reversesynchronization mechanism SY6 are configured similarly to the firstspeed synchronization mechanism SY1.

More exactly, the third-seventh speed synchronization mechanism SY2 islocated between the third speed drive gear 23 and the seventh speeddrive gear 27 and includes a hub HB2 fixed on the first main input shaft11 and a sleeve SL2 provided on an outer peripheral surface of the hubHB2 to be axially movable by means of dog teeth D1 and D2. When thesleeve SL2 moves from the neutral position of FIG. 1 to a third speedin-gear position at one axial side where the dog teeth D2 of the sleeveSL2 mesh (engage) with dog teeth D3 of the third speed drive gear 23,the third speed drive gear 23 connects to the hub HB2 through the sleeveSL2. This enables the third speed drive gear 23 to rotate integrallywith the first main input shaft 11. When the first clutch C1 engages inthis state, the third speed stage is established and rotation of thefirst main input shaft 11 is transmitted to the output shaft 14 throughthe hub HB1, the third speed drive gear 23 and the second-third speeddriven gear 41, thus driving the vehicle in the third speed stage.

On the other hand, When the sleeve SL2 moves from the neutral positionto a seventh speed in-gear position at the other axial side where thedog teeth D2 of the sleeve SL2 mesh (engage) with dog teeth D4 of theseventh speed drive gear 27, the seventh speed drive gear 27 connects tothe hub HB2 through the sleeve SL2. This enables the seventh speed drivegear 27 to rotate integrally with the first main input shaft 11. Whenthe first clutch C1 engages in this state, the seventh speed stage isestablished and rotation of the first main input shaft 11 is transmittedto the output shaft 14 through the hub HB2, the seventh speed drive gear27 and the sixth-seventh speed driven gear 42, thus driving the vehiclein the seventh speed stage.

The fifth speed synchronization mechanism SY3 includes a hub HB3 fixedon the first main input shaft 11 and a sleeve SL3 provided on an outerperipheral surface of the hub HB3 to be axially movable by means of dogteeth D1 and D2. When the sleeve SL3 moves from the neutral position ofFIG. 1 to a fifth speed in-gear position at one axial side where the dogteeth D2 of the sleeve SL3 mesh with dog teeth D3 of the fifth speeddrive gear 25, the fifth speed drive gear 25 connects to the hub HB3through the sleeve SL3. This enables the fifth speed drive gear 25 torotate integrally with the first main input shaft 11. When the firstclutch C1 engages in this state, the fifth speed stage is establishedand rotation of the first main input shaft 11 is transmitted to theoutput shaft 14 through the hub HB3, the fifth speed drive gear 25 andthe fourth-fifth speed driven gear 43, thus driving the vehicle in thefifth speed stage.

The second-sixth speed synchronization mechanism SY4 includes a hub HB4fixed on the auxiliary input shaft 13 and a sleeve SL4 provided on anouter peripheral surface of the hub HB4 to be axially movable by meansof dog teeth D1 and D2. When the sleeve SL4 moves from the neutralposition of FIG. 1 to a second speed in-gear position at one axial sidewhere the dog teeth D2 of the sleeve SL4 mesh with dog teeth D3 of thesecond speed drive gear 22, the second speed drive gear 22 connects tothe hub HB4 through the sleeve SL4. This enables the second speed drivegear 22 to rotate integrally with the auxiliary input shaft 13. When thesecond clutch C2 engages in this state, the second speed stage isestablished and rotation of the second main input shaft 12 istransmitted to the output shaft 14 through the idler gear 32, the gear33, the auxiliary input shaft 13, the hub HB4, the second speed drivegear 22 and the second-third speed driven gear 41, thus driving thevehicle in the second speed stage.

On the other hand, When the sleeve SL4 moves from the neutral positionto a sixth speed in-gear position at the other axial side where the dogteeth D2 of the sleeve SL4 mesh with dog teeth D4 of the sixth speeddrive gear 26, the sixth speed drive gear 26 connects to the hub HB4through the sleeve SL4. This enables the sixth speed drive gear 26 torotate integrally with the auxiliary input shaft 13. When the secondclutch C2 engages in this state, the sixth speed stage is establishedand rotation of the second main input shaft 12 is transmitted to theoutput shaft 14 through the idler gear 32, the gear 33, the auxiliaryinput shaft 13, the hub HB4, the sixth speed drive gear 26 and thesixth-seventh speed driven gear 42, thus driving the vehicle in thesixth speed stage.

The fourth speed synchronization mechanism SY5 includes a hub HB5 fixedon the auxiliary input shaft 13 and a sleeve SL5 provided on an outerperipheral surface of the hub HB5 to be axially movable by means of dogteeth D1 and D2. When the sleeve SL5 moves from the neutral position ofFIG. 1 to a fourth speed in-gear position at one axial side where thedog teeth D2 of the sleeve SL5 mesh with dog teeth D3 of the fourthspeed drive gear 24, the fourth speed drive gear 24 connects to the hubHB5 through the sleeve SL5. This enables the fourth speed drive gear 24to rotate integrally with the auxiliary input shaft 13. When the secondclutch C2 engages in this state, the fourth speed stage is establishedand rotation of the second main input shaft 12 is transmitted to theoutput shaft 14 through the idler gear 32, the gear 33, the auxiliaryinput shaft 13, the hub HB5, the fourth speed drive gear 24 and thefourth-fifth speed driven gear 43, thus driving the vehicle in thefourth speed stage.

The reverse synchronization mechanism SY6 includes a hub HB6 fixed onthe reverse shaft 16 and a sleeve SL6 provided on an outer peripheralsurface of the hub HB6 to be axially movable by means of dog teeth D1and D2. When the sleeve SL6 moves from the neutral position of FIG. 1 toa reverse in-gear position at one axial side where the dog teeth D2 ofthe sleeve SL6 mesh with dog teeth D3 of the reverse drive gear 28, thereverse drive gear 28 connects to the hub HB6 through the sleeve SL6.This enables the reverse drive gear 28 to rotate integrally with thereverse shaft 16. When the second clutch C2 engages in this state, thereverse stage is established and rotation of the second main input shaft12 is transmitted to the first main input shaft 11 through the idlergear 32, the gear 34, the reverse shaft 16, the hub HB6, the reversedrive gear 28 and the reverse driven gear 35, thus rotating the firstmain input shaft 11 in the opposite direction compared to the firstspeed driving, the third speed driving, the fifth speed driving and theseventh speed driving. Further, the sleeve SL2 of the third-seventhspeed synchronization mechanism SY2 moves to the third in-gear position.Therefore, rotation of the first main input shaft 11 is transmitted tothe output shaft 14 through the hub HB2, the third speed drive gear 23and the second-third driven gear 41, and the vehicle backward drives.

Although not illustrated, among the synchronization mechanisms SY1 toSY6, taper-cone-shaped synchro rings are provided between the secondspeed drive gear 22 and the hub HB4, between the third speed drive gear23 and the hub HB2, between the fourth speed drive gear 24 and the hubHB5, between the fifth speed drive gear 25 and the hub HB3, between thesixth speed drive gear 26 and the hub HB4, between the seventh speeddrive gear 27 and the hub HB2, and between the reverse drive gear 28 andthe hub HB6, respectively.

During gear engaging action, tapered surfaces of the synchro ringsfrictionally engage tapered surfaces of the speed drive gears 22 to 28facing the synchro rings. Therefore, rotational speed difference betweenthe dog teeth D2 and the dog teeth D3 and D4 becomes 0, and thus smoothgear engaging action can be carried out. The speed drive gears 23 to 28are individually provided with shifting gears which engage associateddriven gears 41 to 43 and 35 and with dog teeth D3 or D4. On the otherhand, no synchro ring is provided between the first speed drive gear 21and the hub HB1. Moreover, the first speed drive gear 21 is providedonly with dog teeth D3 and not with a shifting gear for engagement withthe driven gear.

In the foregoing, vehicle driving solely by torque from the engine 2,i.e., engine driving, is explained, but assist torque from the electricmotor 3 can also be applied to the first main input shaft 11 in additionto the torque from the engine 2. Moreover, vehicle driving solely bytorque from the electric motor 3 instead of torque from the engine 2,i.e. motor driving (EV driving), is also possible.

The sleeves SL1 to SL6 are moved from the neutral position to thein-gear position and from the in-gear position to the neutral positionby individually associated electric motors or other such actuators (FIG.5A). Driving of the actuators is controlled by the controller. Thecontroller selects a speed stage in response to manipulation of aselector adapted for selecting among, for example, L, D, N, R and Pshift ranges. In particular, when the selector is put in D range, whichis automatic shift mode, the speed stage is automatically selected basedon accelerator pedal depression amount and vehicle speed. In such case,the controller decides desired torque in response to amount ofaccelerator pedal depression and pre-shifts the transmission 1 accordingto the desired torque, thus enabling a rapid gear shifting action.

For example, in a state where the first clutch C1 is engaged and thesecond clutch C2 is disengaged, when desired torque increases duringdriving in the third gear, the controller determines that accelerationis desired and pre-shifts to select the fourth speed stage.Specifically, it performs an up-shift by moving the sleeve SL5 of thefourth speed synchronization mechanism SY5 to the fourth speed in-gearposition. On the other hand, when desired torque decreases duringdriving in the third gear, the controller determines that decelerationis desired and pre-shifts to select the second speed stage.Specifically, it performs a down-shift by moving the sleeve SL4 of thesecond-sixth speed synchronization mechanism SY4 to the second speedin-gear position.

In this connection, despite the controller having output a drive commandto the actuator to move the associated one of the sleeves SL1 to SL6from the neutral position to the in-gear position, the sleeve sometimesdoes not move to the in-gear position, so that the dog teeth D2 of thesleeve cannot mesh with the dog teeth D3 or D4 of the associated one ofthe speed drive gears 21 to 28. This point is explained below withreference to FIGS. 2 and 3. FIGS. 2 and 3 are two-dimensionaldevelopments of the dog teeth D2 of the sleeve SL1 of the first speedsynchronization mechanism SY1 and of the dog teeth D3 of the first speeddrive gear 21, showing the sleeve SL1 in the course of moving to firstspeed in-gear position.

As shown in FIG. 2, the dog teeth D2 and dog teeth D3 both havesubstantially triangular tip portions. The dog teeth D2 move toward thedog teeth D3 in the direction of arrow “A”, and when sloped faces at theends of the dog teeth D1 and D3 contact one another with apices D20 ofthe dog teeth D2 and apices D30 of the dog teeth D3 in a phase-shiftedstate, the dog teeth D2 exert pushing force F1 on the dog teeth D3 inthe direction of arrow “A”. The pushing force F1 produces a reactionforce in the dog teeth D2 (push-aside torque T1) acting in therotational direction and produces a push-aside torque T2 in the dogteeth D3 acting in the opposite direction from that in the dog teeth D2.As a result, the sleeve SL1 (dog teeth D2) moves in the direction ofarrow “A” while pushing aside the dog teeth D3, whereby the sleeve SL1ultimately moves to the first speed in-gear position at which the dogteeth D2 and D3 are completely meshed with each other.

On the other hand, when, as shown in FIG. 3, the apices D20 of the dogteeth D2 or the vicinity thereof abut the apices D30 of the dog teethD3, only the axial direction pushing force F1 acts on the dog teeth D3and no push-aside torques occur in the directions of rotation of the dogteeth D2 and D3. Therefore, the sleeve SL1 cannot advance any farther inthe direction of arrow “A” and the gear engaging action fails. Oneconceivable way to deal with this would be to once move the sleeve SL1in the direction of arrow B (toward the neutral position) until the dogteeth D2 separate from the dog teeth D3 and then move the sleeve SL1back in the direction of arrow “A”.

However, moving the sleeve SL1 in the direction of arrow B delays gearengaging action by the time required for moving the sleeve SL1, so thata rapid shift operation is hard to achieve. Moreover, when the sleeveSL1 is once moved in the direction of arrow B and then moved back in theA direction, the apices D20 and D30 of the dog teeth D2 and D3 may againabut each other and make gear engagement of the sleeve SL1 impossible.In the present embodiment, therefore, the control apparatus for atransmission is configured as set out below in order to realize shiftoperations in a short time even when the apices D20 and D30 of the dogteeth D2 and D3 abut each other.

As an example, a case is explained in the following in which the controlapparatus for a transmission performs gear engagement control of thefirst speed synchronization mechanism SY1 to shift from the third speedstage to the first speed stage when decelerating during EV driving(during EV deceleration driving). In other words, a case in which thefirst main input shaft 11 is powered and the vehicle is driven solely bytorque from the electric motor 3 is taken as an example. FIG. 4 is atiming chart showing examples of vehicle speed during EV decelerationdriving, shift command value, gear stage number of the first main inputshaft 11 (rotating shaft for odd-numbered speed stages; solid line) andgear stage number of the auxiliary input shaft 13 (rotating shaft foreven-numbered speed stages; dashed line), and time-course change ofrotational speed of the first main input shaft 11, auxiliary input shaft13 and other rotating shafts (for example, drive shaft connected to thedrive wheels).

As shown in FIG. 4, during EV deceleration driving, vehicle speedgradually decreases with passage of time t (characteristic curve f1). Inthe course of the decrease, a shift command value designating the thirdspeed stage is maintained until time t1 (characteristic curve f2).Therefore, the first main input shaft 11 is connected through thethird-seventh speed synchronization mechanism SY2 to the third speeddrive gear 23, thus driving the vehicle in the third speed stage(characteristic curve f3). On the other hand, the auxiliary input shaft13 is connected to the second speed drive gear 22 by a pre-shift(characteristic curve f4).

When vehicle speed becomes equal to or slower than a set vehicle speedV1 at time t1 (characteristic curve f1), the shift command value skipsthe second speed stage and designates the first speed stage(characteristic curve f2). As a result, the sleeve SL2 of thethird-seventh speed synchronization mechanism SY2 starts to move fromthe third speed in-gear position to the neutral position (N), and attime t2 the first main input shaft 11 becomes the neutral statedisconnected from the third speed drive gear 23 (characteristic curvef3). Thereafter, at time t4, the sleeve SL1 of the first speedsynchronization mechanism SY1 moves from the neutral position to thefirst speed in-gear position, thus establishing the first speed stage(characteristic curve f3).

During EV deceleration driving, the rotational speed of the auxiliaryinput shaft 13 indicated by a dashed line (characteristic curve f5) andthe rotational speed of the driveshaft indicated by a one-dot-dashedline (characteristic curve f6) decrease with decreasing vehicle speed.On the other hand, the rotational speed of the first main input shaft 11indicated by a solid line (characteristic curve f7) once increases whenthe first main input shaft 11 is in the neutral position between timest3 and t4, which point is discussed further below.

FIG. 5A is a block diagram showing a configuration of the controlapparatus for the transmission according to an embodiment of the presentinvention. This control apparatus includes components for switching thetransmission from third speed stage to first speed stage during EVdeceleration driving. As shown in FIG. 5A, a controller 50 receivessignals from a vehicle speed sensor 51 for detecting vehicle speed, anaccelerator position sensor 52 for detecting amount of depression of theaccelerator pedal, a sleeve position sensor 53 for detecting position ofthe sleeve SL1 of the first speed synchronization mechanism SY1, and arotational speed sensor 54 for detecting rotational speed of theelectric motor 3 (rotor 3 a).

As shown in FIG. 1, a pulse gear 16 a is provided on the reverse shaft16, and, for example, the vehicle speed sensor 51 is constituted as apick-up sensor capable of detecting forward and reverse rotation of thepulse gear 16 a. This is because the auxiliary input shaft 13 andreverse shaft 16 rotate together with the output shaft 14 during thevehicle driving, so that rotational speed of the reverse shaft 16 iscorrelated with vehicle speed and vehicle speed can therefore bedetected by detecting rotation of the reverse shaft 16.

Detecting vehicle speed from rotational speed of the reverse shaft 16 inthis manner makes it possible to increase sensor resolution and enhancevehicle speed detection accuracy compared to the case of detectingvehicle speed from, for example, rotational speed of the driveshaft.This is because rotational speed variation characteristics of thereverse shaft 16 and rotational speed variation characteristics of theauxiliary input shaft 13 indicated by characteristic curve f5 in FIG. 4are the same, and since sensor resolution is therefore higher than thatin the case of characteristic curve f6, vehicle speed can be accuratelydetected. Moreover, rotational speed of the first speed drive gear 21and rotational speed of the reverse shaft 16 are correlated because, asseen in FIG. 1, the first speed drive gear 21 becomes one body with thethird speed drive gear 23 meshed with the second-third speed driven gear41 and therefore rotates together with the reverse shaft 16. Detectingrotation of the reverse shaft 16 with the vehicle speed sensor 51therefore enables rotation of the first speed drive gear 21 also to beaccurately detected.

The sleeve position sensor 53 can, for example, be constituted as aposition sensor connected to the sleeve SL1 of the first speedsynchronization mechanism SY1 and adapted to detect position of a shiftfork which moves together with the sleeve SL1. Alternatively, the sleeveposition sensor 53 can be constituted as a contact switch or the likewhich turns ON when the sleeve SL1 moves to the first-speed in-gearposition.

The controller 50 is configured to include an arithmetic processing unit(a processing circuit) having a processor 50A (CPU), a memory 50Bcoupled to the processor 50A (ROM and RAM) and other peripheralcircuits, and outputs control signals to actuators 55 for axially movingthe sleeves SL1 to SL6 and to a power drive unit 56 for driving theelectric motor 3.

FIG. 5B is a block diagram showing a functional configuration of thecontroller 50. As shown in FIG. 5B, as functional constituents, thecontroller 50 has a control start determiner 501, a gear engagementcommander 502, a gear engagement determiner 503, an actuator controller504, and a motor controller 505. The motor controller 505 has a rotationmatching portion 506 and a phase shifting portion 507.

The control start determiner 501 determines presence or absence of shiftcontrol start condition for shifting from the third speed stage to thefirst speed stage during EV deceleration driving. The shift controlstart condition is present when vehicle speed during EV driving in thethird speed stage is equal to or slower than a predetermined speed v1(time t1 in FIG. 4). Therefore, the control start determiner 501 usesthe current shift command value and the signal from the vehicle speedsensor 51 to determine presence or absence of the shift control startcondition.

After the control start determiner 501 determines presence of the shiftcontrol start condition, the gear engagement commander 502 determinespresence or absence of engagement control start condition, and whenpresence of the engagement control start condition is determined,instructs start of a gear engaging action of the first speedsynchronization mechanism SY1. The engagement control start condition issatisfied when difference between rotational speed of the sleeve SL1 ofthe first speed synchronization mechanism SY1 (sleeve rotational speedN1 s) and rotational speed of the first speed drive gear 21 (gearrotational speed N1 g) is equal to or smaller than a predeterminedvalue. The rotational speed of the sleeve SL1 is correlated to therotational speed of the first main input shaft 11, so that the sleeverotational speed N1 s (rpm) during EV driving can be obtained using thesignal from the rotational speed sensor 54. On the other hand, the gearrotational speed N1 g (rpm) can be obtained using the signal from thevehicle speed sensor 51.

The gear engagement determiner 503 uses the signal from the sleeveposition sensor 53 to determine whether the dog teeth D2 of the sleeveSL1 have engaged with the dog teeth D3 of the first speed drive gear 21,i.e., to determine whether the gear engaging action is prevented in thecourse of moving the sleeve SL1 from the neutral position to the firstspeed in-gear position. More specifically, the gear engagementdeterminer 503 uses the signal from the sleeve position sensor 53 tocalculate moving distance of the sleeve SL1 per unit time, i.e., sleevemoving speed Vs. Then, when the apices of the dog teeth D2 and D3 abuteach other to slow sleeve moving speed Vs to or below a predeterminedvalue Vs1, the gear engagement determiner 503 determines that the gearengaging action is prevented.

When the control start determiner 501 determines that the shift controlstart condition is satisfied, the actuator controller 504 outputs acontrol signal to the actuator 55 to move the sleeve SL2 of thethird-seventh speed synchronization mechanism SY2 from the third speedin-gear position to the neutral position. In addition, when the gearengagement commander 502 instructs start of the gear engaging action ofthe first speed synchronization mechanism SY1, the actuator controller504 outputs a control signal to the actuator 55 to move the sleeve SL1of the first speed synchronization mechanism SY1 from the neutralposition to the first speed in-gear position.

The motor controller 505 outputs a control signal to the power driveunit 56 to control operation of the electric motor 3, i.e., to controlrotating activity of the first main input shaft 11. More specifically,after the sleeve SL2 of the third-seventh speed synchronizationmechanism SY2 has moved from the third speed in-gear position to theneutral position, the rotation matching portion 506 controls rotation ofthe electric motor 3 to match sleeve rotational speed N1 s detected fromthe signal from the rotational speed sensor 54 with gear rotationalspeed N1 g detected from the signal from the vehicle speed sensor 51.

When the gear engagement determiner 503 determines that engaging the dogteeth D2 of the sleeve SL1 of the first speed synchronization mechanismSY1 with the dog teeth D3 of the first speed drive gear 21 has failed,the phase shifting portion 507 outputs a control signal to the powerdrive unit 56, thereby driving the electric motor 3 to output apredetermined torque and shifting the phase of the sleeve SL1 withrespect to the first speed drive gear 21.

FIG. 6 is a flowchart showing an example of processing executed by theprocessor 50A of the controller 50. The processing indicated by thisflowchart is initiated when the control start determiner 501 determinesthat the shift control start condition is established.

First, in S1 (S: processing step), the actuator controller 504 outputs acontrol signal to the actuator 55 to move the third-speed sleeve SL2from the third speed in-gear position to the neutral position. Next, inS2, the rotation matching portion 506 outputs a control signal to thepower drive unit 56 to match rotational speed N1 s of the first-speedsleeve SL1 with rotational speed N1 g of the first speed drive gear 21.The processing of S2 is continued until rotational speed differencebetween the sleeve rotational speed N1 s and the gear rotational speedN1 g becomes equal to or smaller than a predetermined value and the gearengagement commander 502 determines that the engagement control startcondition is established.

Next, in S3, the actuator controller 504 outputs a control signal to theactuator 55 to move the first-speed sleeve SL1 from the neutral positionto the first speed in-gear position at a set speed Vs0. The drivingforce of the actuator 55, i.e., voltage Va applied to the actuator 55,at this time is a predetermined value Va0. Next, in S4, the gearengagement determiner 503 determines whether moving speed Vs of thesleeve SL1 becomes equal to or slower than a predetermined value Vs1.The predetermined value Vs1 is set in advance to be greater than 0 andsmaller than the set speed Vs0. When the result in S4 is YES, theprogram goes to S5, and when NO, skips S5 to S8 and goes to S9.

In S5, a timer begins to count up. Next, in S6, whether the timer hascounted a predetermined time Δt1, i.e., whether predetermined time Δt1has passed since the sleeve moving speed Vs became equal to or slowerthan the predetermined value Vs1 is determined. When the result in S6 isNO, the program returns to S3 to repeat the same processing. When theresult in S6 is YES, the program goes to S7.

In S7, the actuator controller 504 lowers actuator driving force byreducing a voltage applied to the actuator 55 (actuator voltage Va) fromthe predetermined value Va0 to a predetermined value Va1. Next, in S8,the phase shifting portion 507 outputs a control signal to the powerdrive unit 56 to drive the electric motor 3 to output a predeterminedmotor torque MT1. This forcibly shifts phase of the sleeve SL1 withrespect to the first speed drive gear 21.

Next, in S9, the gear engagement determiner 503 uses the signal from thesleeve position sensor 53 to determine whether the dog teeth D2 and D3are completely in gear. This determination corresponds to determiningwhether the sleeve SL1 moved to the first speed in-gear position L1.When the result in S9 is NO, the program returns to S3 repeat the sameprocessing. When the result in S9 is YES, gear engagement control of thefirst speed synchronization mechanism SY1 is terminated.

In the following, operation of the control apparatus for a transmissionin accordance with this embodiment of the present invention is explainedin more detail with reference to FIG. 7. FIG. 7 is a timing chartshowing examples of time-course change of motor torque MT generated bythe electric motor 3, axial movement amount (shift stroke L) of thesleeve SL1, sleeve moving speed Vs, elapsed time Δt1 on timer, andactuator voltage Va. Times t10 and t17 in FIG. 7 respectively correspondto times t3 and t4 in FIG. 4. The gear engagement control is performedduring the period between times t10 and t17.

Since time t10 in FIG. 7 is later than time t2 in FIG. 4, thethird-speed sleeve SL2 is already moving from the third speed in-gearposition toward the neutral position at time 10. At time t10, a controlsignal is output to the power drive unit 56 to implement matching ofrotational speed N1 s of the first-speed sleeve SL1 with gear rotationalspeed N1 g of the first speed drive gear 21 (S2). As a result, the motortorque MT increases and, as shown by characteristic curve f7 in FIG. 4,the rotational speed of the first main input shaft 11 increases. Uponcompletion of the rotational speed matching, the motor torque MT becomes0. Following this, a control signal (predetermined value Va0) is outputto the actuator 55 at time t11 in FIG. 7 (S3). Sleeve moving speed Vstherefore becomes predetermined speed Vs0, and the sleeve SL1 startsmoving from neutral position, where shift stroke L=0, toward the firstspeed in-gear position L1.

By matching the rotations of the sleeve SL1 and the first speed drivegear 21 in this manner, the dog teeth D2 and D3 can be smoothlygear-engaged with each other even without interposing a synchro ringbetween the first-speed sleeve SL1 and the first speed drive gear 21. Asa result, synchronization between the first speed drive gear 21 and asynchro ring is unnecessary, so that time required for gear engagementcan be shortened.

Now assume a case in which, at time t12 when the shift stroke is L2before the sleeve SL1 reaches the first speed in-gear position L1, theapices of the dog teeth D2 and D3 abut each other, i.e. that apexcollision occurs (the dog teeth D2 and D3 catch on each other). In thiscase, the sleeve moving speed Vs decreases, and it is determined thatapex collision of the dog teeth D2 and D3 occurs when sleeve movingspeed Vs becomes equal to or slower than the predetermined value Vs1 attime t13, whereupon the timer begins to count (S5). This enables promptgear engaging action because presence or absence of apex collision ofthe dog teeth D2 and D3 can be determined before the sleeve moving speedVs decreases to 0 (before time t14).

When the timer count reaches predetermined time Δt1 at time t15,actuator voltage Va is decreased (S7). Axial direction pushing force F1(FIG. 3) exerted on the dog teeth D3 therefore decreases. When theactuator voltage Va decreases to the predetermined value Va1 at timet16, a predetermined motor torque MT1 is output between time t16 andtime t17 (S8). By outputting the motor torque MT1 after decreasing theactuator voltage Va in this manner, the first main input shaft 11 can beeasily rotated while abutting the dog teeth D2 and D3 with each other.As a result, phase of the dog teeth D2 with respect to the dog teeth D3changes to resolve apex collision condition of the dog teeth D2 and D3.

Moreover, since the actuator voltage Va is decreased after the timercount reaches the predetermined time Δt1, output of motor torque MT1becomes unnecessary in a case where the sleeve SL1 is again to be movedat prescribed speed Vs0 by applying actuator voltage Va0 before elapseof predetermined time Δt1. As a result, prompt gear-engage actionbecomes possible in a case where, for example, the apices of the dogteeth D2 and D3 spontaneously shift in phase before elapse of thepredetermined time Δt1.

When output of motor torque MT1 is stopped at time t17, the dog teeth D2and D3 are shifted in phase. As a result, the sleeve SL1 again becomesmovable toward the first speed in-gear position L1 and shift stroke Lexpands. When the sleeve SL1 reaches the first speed in-gear position L1at time t18, the gear engaging action is complete and first speed stageis established.

This embodiment of the present embodiment can achieve advantages andeffects such as the following:

(1) The transmission 1 includes the first main input shaft 11 rotatableby the electric motor 3, the hub HB1 rotatably provided concentricallyon the first main input shaft 11, the sleeve SL1 which has the dog teethD2 and is supported on the hub HB1 via the dog teeth D2 to be axiallymovable, the first speed drive gear 21 rotatably provided concentricallyon the first main input shaft 11 and having the dog teeth D3 arrangedbeside the sleeve SL1 in the axial direction to be engageable with thedog teeth D2, and the actuator 55 for moving the sleeve SL1 between theneutral position where the dog teeth D2 are apart from the dog teeth D3and the first speed in-gear position where the dog teeth D2 engage withthe dog teeth D3, in which, when the dog teeth D2 are in the neutralposition, the hub HB1 is supported to be integrally rotatable with thefirst main input shaft 11 and the first speed drive gear 21 is supportedto be rotatable relative to the first main input shaft 11, and when thedog teeth D2 move to the first speed in-gear position, the first speeddrive gear 21 becomes integrally rotatable with the first main inputshaft 11 to enable establishment of the first speed stage (FIG. 1). Thecontrol apparatus for this transmission 1 includes the gear engagementcommander 502 for outputting the gear engagement command of the sleeveSL1, the actuator controller 504 for controlling the actuator 55responsive to output of the gear engagement command so that the sleeveSL1 moves from the neutral position to the first speed in-gear position,the gear engagement determiner 503 for determining whether the gearengaging action of the sleeve SL1 is prevented in the course of movingthe sleeve SL1 from the neutral position to the first speed in-gearposition using the actuator 55, and the motor controller 505 (the phaseshifting portion 507) for controlling the electric motor 3 responsive todetermination by the gear engagement determiner 503 that the gearengaging action of the sleeve SL1 is prevented so as to rotate the firstmain input shaft 11 and shift the phase of the dog teeth D2 with respectto the dog teeth D3 (FIGS. 5A and 5B).

Thus, when the gear engaging action of sleeve SL1 is prevented, thesleeve SL1 is not returned to the neutral position but the motor torqueMT1 is added to the first main input shaft 11 to shift the phase of thedog teeth D2 with respect to the dog teeth D3, whereby time required forthe gear engaging action can be shortened and rapid gear shifting actionachieved.

(2) The gear engagement determiner 503 uses the signal from the sleeveposition sensor 53 to calculate axial direction moving speed Vs of thesleeve SL1 and determines that the gear engaging action of the sleeveSL1 is prevented when the sleeve moving speed Vs decreases to or belowthe predetermined value Vs1 greater than 0 (FIG. 7). Therefore, beforesleeve moving speed Vs becomes 0, it can be determined that gearengagement is disabled owing to, for example, abutment of the dog teethD2 and D2 apices with each other, thus making it possible to promptlystart gear engagement control for resolving abutment between the apices(apex collision).

(3) When the prevented state of gear engaging action of the sleeve SL1determined by the gear engagement determiner 503 continues forpredetermined time Δt1, the phase shifting portion 507 controls theelectric motor 3 to shift phase of the dog teeth D2 with respect to thedog teeth D3 (FIG. 7). This suspension of motor torque MT1 addition bythe predetermined time Δt1 following occurrence of the gear engagingaction prevention makes it possible to implement gear engaging actionpromptly without addition of motor torque MT1 in a case where the phaserelation between the dog teeth D2 and D3 shifts spontaneously withinpredetermined time Δt1.

(4) When the gear engagement determiner 503 determines that eh gearengaging action of the sleeve SL1 is prevented, the actuator controller504 decreases driving force of the actuator 55, and after the drivingforce of the actuator 55 is decreased by the actuator controller 504,the phase shifting portion 507 controls the electric motor 3 to shiftthe phase of the dog teeth D2 with respect to the dog teeth D3 (FIG. 7).Therefore, since motor torque is added in a state that pushing force F1between the dog teeth D2 and D3 is reduced, the phase relation betweenthe dog teeth D2 and D3 can be easily shifted because the first maininput shaft 11 can be easily rotated by addition of small motor torqueMT1.

(5) The rotation matching portion 506 controls the electric motor 3 tomatch rotational speed N1 g of the first speed drive gear 21 detectedfrom the signal from the vehicle speed sensor 51 and rotational speed N1s of the sleeve SL1 detected from the signal from the rotational speedsensor 54 (S2), and after the rotation matching portion 506 controls theelectric motor 3 to match the rotational speed N1 g of the first speeddrive gear 21 and the rotational speed N1 s of the sleeve SL1, theactuator controller 504 controls the actuator 55 to move the sleeve SL1from the neutral position to the first speed in-gear position (S3). Thisrotational matching of the dog teeth D2 and D3 by adding motor torque tothe first main input shaft 11 makes a synchro ring unnecessary in thefirst speed synchronization mechanism SY1. Therefore, time fromestablishment of shift control start condition by the control startdeterminer 501 to completion of the gear engagement of the first speedsynchronization mechanism SY1 can be shortened.

Although operation in the case of shifting from third speed stage tofirst speed stage during EV deceleration driving is explained in theforegoing, the control apparatus for the transmission according to theembodiment of the present invention can be similarly applied to otherdriving operations. For example, application is also possible in a casethat the vehicle starts moving by EV driving from a stopped state atvehicle speed 0. In this case, sleeve rotational speed N1 s and gearrotational speed N1 g are initially both 0 and rotation speed matchingof the two is unnecessary. It therefore suffices for the controller 50to begin gear engagement control processing from S3 of FIG. 6.

Although the control apparatus for the transmission is applied for gearengagement control of the first speed synchronization mechanism SY1 inthe above embodiment, it can be similarly applied for gear engagementcontrol of the third-seventh speed synchronization mechanism SY2 or thefifth speed synchronization mechanism SY3. In other words, the controlapparatus for the transmission according to the embodiment of thepresent invention can be similarly applied for gear engagement controlof the synchronization mechanisms SY2 and SY3 located around the firstmain input shaft 11 connected to the electric motor 3. Alternatively, itis possible to connect an electric motor to the auxiliary input shaft 13and use the auxiliary input shaft 13 instead of the first main inputshaft 11 as a rotating shaft rotatable by an electric motor. In thiscase, the control apparatus for the transmission according to theembodiment of the present invention can be similarly applied for gearengagement control of the second-sixth speed synchronization mechanismSY4 or for gear engagement control of the fourth speed synchronizationmechanism SY5.

Therefore, although in the above embodiment, the first speed drive gear21 as a rotor arranged beside the sleeve SL1 in the axial direction hasonly the dog teeth D3 (passive dog teeth) engageable with the axiallymovable dog teeth D2 (movable dog teeth), a rotor may have dog teeth D3or D4 and a shifting gear similarly to the other drive gears 22 to 28.Although in the above embodiment, the hub HB1 is provided to berotatable integrally with the first main input shaft 11 (rotating shaft)through the planetary gear unit 20, and the first speed drive gear 21(rotor) is provided to be rotatable relative to the first main inputshaft 11, a transmission can be of any configuration insofar as a hub issupported to be rotatable integrally with a rotating shaft and a rotoris supported to be rotatable relative to the rotating shaft when the dogteeth D2 are in a neutral position, and the rotor is rotatableintegrally with the rotating shaft to establish a predetermined speedstage when the dog teeth D2 move to a gear engaging position. Therotating shaft is not limited to the first main input shaft 11 and therotor is not limited to the first speed drive gear 21.

Although in the above embodiment, the actuator 55 for moving the sleevefrom a neutral position and a gear engaging position is constituted ofan electric motor, the actuator can be constituted by other components(a hydraulic cylinder or the like, for example). Although in the aboveembodiment, the sleeve moving speed Vs is detected from the signal fromthe sleeve position sensor 53, a moving speed detector is not limited tothis configuration. In the aforesaid embodiment, when the state of thegear engagement determiner 503 having determined that the gear engagingaction is prevented continues for the predetermined time Δt1, the motorcontroller 505 (phase shifting portion 507) operates as a motorcontroller for controlling the electric motor 3 to shift the phase ofthe dog teeth D2 constituting movable dog teeth with respect to the dogteeth D3 constituting passive dog teeth, but the motor torque can beadded without waiting for the predetermined time Δt1 to pass.

In the above embodiment, when the gear engagement determiner 503determines that gear engaging action is prevented, the electric motor 3is controlled to shift the phase (change rotational position) of the dogteeth D2 with respect to the dog teeth D3 after the driving force of theactuator 55 is decreased. However, it is instead possible to attemptchanging the rotational position of the dog teeth without decreasing thedriving force of the actuator 55. Although in the above embodiment, therotational speed N1 g of the rotor (first speed drive gear 21) isdetected from the signal from the vehicle speed sensor 51, a firstrotational speed detector is not limited to this configuration. Althoughin the above embodiment, the rotational speed N1 s of the sleeve SL1 isdetected from the signal from the rotational speed sensor 54, a secondrotational speed detector is not limited to this configuration.

The above embodiment can be combined as desired with one or more of theaforesaid modifications. The modifications can also be combined with oneanother.

According to the present invention, when an engaging action of a sleeveis prevented, a rotating shaft is rotated by an electric motor to changea rotational position of movable dog teeth of a sleeve relative topassive dog teeth of a rotor. Therefore, even if apices of the movableand passive dog teeth abut each other and a gear engaging action isprevented, it is unnecessary to return the sleeve to a neutral position.As a result, time required for the gear engaging action can be shortenedand it is possible to carry out prompt shifting action.

Above, while the present invention has been described with reference tothe preferred embodiments thereof, it will be understood, by thoseskilled in the art, that various changes and modifications may be madethereto without departing from the scope of the appended claims.

What is claimed is:
 1. A control apparatus for a transmission, thetransmission comprising: a rotating shaft rotatable by an electricmotor; a hub configured to rotate integrally with the rotating shaft; asleeve including movable dog teeth and supported on the hub through themovable dog teeth in a manner movable in an axial direction; a rotorarranged beside the sleeve in the axial direction in a manner rotatablerelative to the rotating shaft and including passive dog teethengageable with the movable dog teeth; and an actuator configured tomove the sleeve from a neutral position where the movable dog teeth isapart from the passive dog teeth so that the rotor is rotatable relativeto the rotating shaft to a gear engaging position where the movable dogteeth engage with the passive dog teeth so that the rotor is rotatableintegrally with the rotating shaft to establish a predetermined speedstage, the control apparatus comprising: a gear engagement commanderconfigured to output a gear engagement command of the sleeve; anactuator controller configured to control the actuator to move thesleeve from the neutral position to the gear engaging position when thegear engagement command is output; a gear engagement determinerconfigured to determine whether an engagement of the sleeve is preventedin a course of moving the sleeve from the neutral position to the gearengaging position; and a motor controller configured to control theelectric motor to rotate the rotating shaft so as to change a rotationalposition of the movable dog teeth relative to the passive dog teeth whenit is determined by the gear engagement determiner that the engagementof the sleeve is prevented.
 2. The apparatus according to claim 1,further comprising a moving speed detector configured to detect a movingspeed of the sleeve in the axial direction, wherein the gear engagementdeterminer determines that the engagement of the sleeve is preventedwhen the moving speed of the sleeve detected by the moving speeddetector becomes equal to or slower than a predetermined value, thepredetermined value being greater than
 0. 3. The apparatus according toclaim 1, wherein the motor controller controls the electric motor so asto change the rotational position of the movable dog teeth relative tothe passive dog teeth when a condition that it is determined by the gearengagement determiner that the engagement of the sleeve is preventedcontinues for a predetermined time.
 4. The apparatus according to claim1, wherein the actuator controller decreases a driving force of theactuator when it is determined by the gear engagement determiner thatthe engagement of the sleeve is prevented, and the motor controllercontrols the electric motor so as to change the rotational position ofthe movable dog teeth relative to the passive dog teeth after thedriving force of the actuator is decreased by the actuator controller.5. The apparatus according to claim 1, further comprising: a firstrotational speed detector configured to detect a rotational speed of therotor; and a second rotational speed detector configured to detect arotational speed of the sleeve, wherein the motor controller controlsthe electric motor so that the rotational speed of the rotor detected bythe first rotational speed detector and the rotational speed of thesleeve detected by the second rotational speed detector match with eachother, and the actuator controller controls the actuator to move thesleeve from the neutral position to the gear engaging position, afterthe electric motor is controlled by the motor controller so that therotational speed of the rotor and the rotational speed of the sleevematch.
 6. The apparatus according to claim 1, wherein the rotorcomprises a first speed drive gear, and when the movable dog teeth moveto the gear engaging position, a first speed stage is established. 7.The apparatus according to claim 1, wherein the transmission furthercomprises: a first clutch; a second clutch; a first input shaftconnected to a prime mover through the first clutch; a second inputshaft arranged parallel to the first input shaft and connected to theprime mover through the second clutch; and an output shaft arrangedparallel to the first input shaft so that a torque from the first inputshaft or the second input shaft is transmitted to the output shaft,wherein the rotating shaft is the first input shaft or the second inputshaft, a torque from the rotating shaft is transmitted to the outputshaft through the rotor.
 8. A control method for a transmission, thetransmission comprising: a rotating shaft rotatable by an electricmotor; a hub configured to rotate integrally with the rotating shaft; asleeve including movable dog teeth and supported on the hub through themovable dog teeth in a manner movable in an axial direction; a rotorarranged beside the sleeve in the axial direction in a manner rotatablerelative to the rotating shaft and including passive dog teethengageable with the movable dog teeth; and an actuator configured tomove the sleeve from a neutral position where the movable dog teeth isapart from the passive dog teeth so that the rotor is rotatable relativeto the rotating shaft to a gear engaging position where the movable dogteeth engage with the passive dog teeth so that the rotor is rotatableintegrally with the rotating shaft to establish a predetermined speedstage, the control method comprising: outputting a gear engagementcommand of the sleeve; controlling the actuator to move the sleeve fromthe neutral position to the gear engaging position when the gearengagement command is output; determining whether an engagement of thesleeve is prevented in a course of moving the sleeve from the neutralposition to the gear engaging position by the actuator; and controllingthe electric motor to rotate the rotating shaft so as to change arotational position of the movable dog teeth relative to the passive dogteeth when it is determined that the engagement of the sleeve isprevented.
 9. The method according to claim 8, further comprisingdetecting a moving speed of the sleeve in the axial direction, whereinthe determining includes determining that the engagement of the sleeveis prevented when the moving speed of the sleeve detected becomes equalto or slower than a predetermined value, the predetermined value beinggreater than
 0. 10. The method according to claim 8, wherein thecontrolling the electric motor includes controlling the electric motorso as to change the rotational position of the movable dog teethrelative to the passive dog teeth when a condition that it is determinedthat the engagement of the sleeve is prevented continues for apredetermined time.
 11. The method according to claim 8, wherein thecontrolling the actuator includes decreasing a driving force of theactuator when it is determined that the engagement of the sleeve isprevented, and the controlling the electric motor includes controllingthe electric motor so as to change the rotational position of themovable dog teeth relative to the passive dog teeth after the drivingforce of the actuator is decreased.
 12. The method according to claim 8,further comprising detecting a rotational speed of the rotor and arotational speed of the sleeve, wherein the controlling the electricmotor includes controlling the electric motor so that the rotationalspeed of the rotor detected and the rotational speed of the sleevedetected match with each other, and the controlling the actuatorincludes controlling the actuator to move the sleeve from the neutralposition to the gear engaging position, after the electric motor iscontrolled so that the rotational speed of the rotor and the rotationalspeed of the sleeve match.
 13. A control apparatus for a transmission,the transmission comprising: a rotating shaft rotatable by an electricmotor; a hub configured to rotate integrally with the rotating shaft; asleeve including movable dog teeth and supported on the hub through themovable dog teeth in a manner movable in an axial direction; a rotorarranged beside the sleeve in the axial direction in a manner rotatablerelative to the rotating shaft and including passive dog teethengageable with the movable dog teeth; and an actuator configured tomove the sleeve from a neutral position where the movable dog teeth isapart from the passive dog teeth so that the rotor is rotatable relativeto the rotating shaft to a gear engaging position where the movable dogteeth engage with the passive dog teeth so that the rotor is rotatableintegrally with the rotating shaft to establish a predetermined speedstage, the control apparatus comprising a processor configured toperform: outputting a gear engagement command of the sleeve; controllingthe actuator to move the sleeve from the neutral position to the gearengaging position when the gear engagement command is output;determining whether an engagement of the sleeve is prevented in a courseof moving the sleeve from the neutral position to the gear engagingposition by the actuator; and controlling the electric motor to rotatethe rotating shaft so as to change a rotational position of the movabledog teeth relative to the passive dog teeth when it is determined thatthe engagement of the sleeve is prevented.
 14. The apparatus accordingto claim 13, further comprising a moving speed detector configured todetect a moving speed of the sleeve in the axial direction, wherein theprocessor is configured to perform determining that the engagement ofthe sleeve is prevented when the moving speed of the sleeve detected bythe moving speed detector becomes equal to or slower than apredetermined value, the predetermined value being greater than
 0. 15.The apparatus according to claim 13, wherein the processor is configuredto perform controlling the electric motor so as to change the rotationalposition of the movable dog teeth relative to the passive dog teeth whena condition that it is determined that the engagement of the sleeve isprevented continues for a predetermined time.
 16. The apparatusaccording to claim 13, wherein the processor is configured to performdecreasing a driving force of the actuator when it is determined thatthe engagement of the sleeve is prevented, and controlling the electricmotor so as to change the rotational position of the movable dog teethrelative to the passive dog teeth after the driving force of theactuator is decreased.
 17. The apparatus according to claim 13, furthercomprising: a first rotational speed detector configured to detect arotational speed of the rotor; and a second rotational speed detectorconfigured to detect a rotational speed of the sleeve, wherein theprocessor is configured to perform controlling the electric motor sothat the rotational speed of the rotor detected by the first rotationalspeed detector and the rotational speed of the sleeve detected by thesecond rotational speed detector match with each other, and controllingthe actuator to move the sleeve from the neutral position to the gearengaging position after the electric motor is controlled so that therotational speed of the rotor and the rotational speed of the sleevematch.
 18. The apparatus according to claim 13, wherein the rotorcomprises a first speed drive gear, and when the movable dog teeth moveto the gear engaging position, a first speed stage is established. 19.The apparatus according to claim 13, wherein the transmission furthercomprises: a first clutch; a second clutch; a first input shaftconnected to a prime mover through the first clutch; a second inputshaft arranged parallel to the first input shaft and connected to theprime mover through the second clutch; and an output shaft arrangedparallel to the first input shaft so that a torque from the first inputshaft or the second input shaft is transmitted to the output shaft,wherein the rotating shaft is the first input shaft or the second inputshaft, a torque from the rotating shaft is transmitted to the outputshaft through the rotor.